LEGO

LEGO’s turn table has considerable friction and rotating a model at an exhibition for a whole day would ruin it. A thrust ball bearing is necessary to decrease the friction. I previously 3D printed a large bearing for my Unikitty. For this year’s exhibition I needed a smaller thrust ball bearing so I designed a new medium sized ball bearing. It includes liftarms to hold a worm wheel which results in a rotation ratio of 1:78. You can download the model from A360 and GrabCAD.

For more than a year I have the pleasure to work in an office in the John Britten building at the University of Canterbury. The office is light, friendly and spacious. I should be more than happy but this building comes with a twist. It is smart. The room has a motion sensor and a temperature sensor. The lights are suppose to go on when activity is detected and the window is suppose to open when it becomes too hot in the room. Notice that this smart building does not have the ability to regulate the heaters. If I switch the heater fully on and thereby create a little sauna then the building will open the window instead of regulating down the heater. I am not sure if this is smart.

The biggest problem is that the window’s behaviour could best be described as neurotic. It opens and closes nervously without considering the noise it makes or the noise that the construction site outside is creating. The only way to tame this autonomous monster is to log into a website and set the window to manual. There is no switch or lever that I could use.

LEGO EV3 Robot Measures the Environment

So I ended up creating a little LEGO robot that would log the environment of the office and the opening of the window in the hope to detect a pattern. Something to convince me that there is method in this madness. Other than that the windows close at 5pm sharp I could not. But along the way I learned a bit more about information visualization on the web and how to to create a useful little logging robot. Have a look at the graph that I produced.

Bricklink’s Stud.io software for building virtual LEGO models now support Sketchfab. You can upload your model directly from Stud.io to their website and then embed it into your web page. I used my 8230 Policy Buggy model to test the system.

It is still difficult to rotate heavy objects with LEGO and hence I designed an ultra compact LEGO compatible ball bearing. it is only 6 studs wide and two studs high. I also added two lift arms. You can put a worm wheel in there to rotate the turn table. The 3D model is available for download from Autodesk. You may need Fusion 360 to work with the model.

Assembled model

Top view

3D Printed versions

This ball bearing is so small that you need a very high resolution printer to get good results. Some of the wall thicknesses could be to small to get printed on low quality printers. I will now be working on a slightly bigger version that can be printed on more affordable printers.

I created this LEGO compatible Raspberry Pi mount so that I can add it to my BrickPi robot. You can use two pins or axles to close the lock. You can download the latest version of the 3D model from Autodesk and you may need Fusion 360 to work with the file. An optimized version for for affordable 3D printers is also available. I increased the tolerances in this model. I also uploaded it to GrabCAD.

I created a small stand for displaying up to 50 Minifigures. It is lightweight but still very stable. It takes advantage of the original collectible minifigures plates. The coloring can be adjusted to your needs. The coloring displayed matches the “The Simpsons” theme. The 3D file is available for Stud.io. and the MOC is also listed at Rebrickable.